A local journalist was gunned down in the Somali capital of Mogadishu, becoming the sixth journalist killed so far this year and putting the east African nation on track to have its deadliest year ever for media workers.

Ahmed Addow Anshur, who worked at a local radio station, was murdered by four armed assailants on motorcycles near a market midday Wednesday, according to the National Union for Somali Journalists (NUSOJ). NUSOJ said the attackers escaped the scene and the motive for the killing is not yet known.

In a statement, the NUSOJ said the targeting of journalists is part of a concerted effort to "undermine the media freedom and freedom of expression," but the organization's Secretary General, Mohammed Ibrahim, said it's often difficult to tell who is actually be behind the attacks.

Somalia has been rocked by violence for the past two decades as the transitional government battles militant Islamists, including the al Qaeda-allied terrorist organization al-Shabaab, for control of the country. Al-Shabaab, which includes in its ranks several American-born fighters such as the rapping jihadist Omar Hammami, occasionally claims responsibility or is blamed for the killings, but other times -- such as in Anshur's case -- the journalists are gunned down in areas controlled by the government.

There are also a variety of violent criminal gangs to consider, Ibrahim said, not to mention journalists who are simply caught in the crossfire.

"[The journalists] know that it's risky, it's deadly, but they respect their profession," said Ibrahim, a veteran Somali journalist who is the first recipient of the Galloway Family Foundation Fellowship for International Investigative Reporting at the ABC News Brian Ross Investigative Unit. "They report to the outside world the situation on the ground. It is a great bravery."

Before coming to the U.S., Ibrahim contributed reporting from Somalia to the New York Times and worked closely with Pulitzer prize-winning Times reporter Jeffrey Gettleman.

The United Nations special representative to Somalia condemned Anshur's murder in a statement today and said journalism in the war-torn nation is "essential to a free and functioning society."

"It is well known that Somali journalists have the most difficult working conditions in the world," the U.N. representative, Dr. Augustine Mahiga, said. "But that does not make it any easier to accept when one is brutally killed. Ahmed Addow Anshur was targeted in cold blood for carrying out his doing his job as a professional journalist..."

In all, the CPJ counts 41 journalists that have been killed in Somalia since 1992 and has named the country the most dangerous on the continent for media workers. The deadliest year to date was 2009, in which nine journalists were killed.